When is a G-Claron a Dagor?

[sanking]

I have seen it stated that some of the older G-Clarons are of Dagor design while the newer ones are the so-called split Dagor, or plasmat desing. Just wondering if anyone has some good data on the G-Clarons showing the eary design and when the design changed from Dagor to plasmat design?

Also, is there a way to know when this change took place by serial number?

Sandy

 

[cspirz]

This thread might help:
http://largeformatphotography.info/lfforum/topic/499571.html

 

[sanking]

This thread might help:
http://largeformatphotography.info/lfforum/topic/499571.html

Thanks. I determined from this thread that one of my G-Claron lenses, a 210mm, is of modified Dagor design, while the other, a 240mm, is a plasmat. Now I am wondering if anyone has made any tests to determine if the actual circle of illumination of the two designs is different? The coverage figures that Schenider gives is not useful for many people since they are much too conservative for photogaphers who primarily contact print.

Sandy

 

[Steve Hamley]

Sandy,

IIRC, Jim Galli had some info about them posted somewhere; maybe he'll look in on us. Or maybe my memory is faulty!

Steve

 

[jimgalli]

Sandy, I don't have any numbers. The "Dagor" formula G-Clarons seem to date roughly 1967-69 or so. The filter ring is smaller in every case. 210 is 40.5 where the later plasmat is 49. The 240mm is 46mm where the plasmat is 52mm. The 150 is 30.5 where the plasmat is 35.5mm. Both have similar 82 degree coverage. I'm still looking for a 270 in early mount to see if it is also Dagor formula. I have an early 355 in the smaller barrel. 67mm filter instead of 77mm on the later one. It is NOT a Dagor type. Plasmat as later. So the unknowns are 270 and 305mm. Interesting perhaps only to me: I have a combination 240 front group, 210 rear group dagor type that lands right in the middle at 225mm and seems to be sharper than the rest! It has displaced almost all of my 210's and 240's. Covers like a 240 and has most of the wideness of a 210. Plus it just seems to have extraordinary contrast rendition. It acts just like my 355 Kern Gold Dot. This is all tounge-in-cheek FWIW YMMV etc. etc. I don't claim to be any expert, just a happy user.

 

[sanking]

Sandy, I don't have any numbers. Both have similar 82 degree coverage.

Actually, that is what I was interested in knowing, i.e. if the Dagor design and plasmat design have similar coverage. That they both have 82 degree coverage answers my question. I would have guessed that the Dagor design covers slightly more.

Sandy